A motorized anti-plaque toothbrush comprises a handle (1) at one end of which is a cleaning/massaging head (3), in particular a brushing head, which rotates about an axis which is approximately perpendicular to the longitudinal axis of the handle (1) and is turned with a continuous one-way rotary motion or with a reciprocating rotary motion by a motor, preferably an electric motor, housed in the handle (1). According to the invention, the cleaning/massaging head (3) is composed of at least two separate cleaning/massaging tool parts (4, 5) that are supported coaxially with respect to each other in such a way that they can rotate relative to each other, being turned in mutually opposite directions in the case of continuous one-way rotation and in phase opposition to each other in the case of reciprocating rotation.